With the development of micro/nanometer optoelectronic integrated technology, more and more cores are integrated into a chip, the size of a device is continuously reduced, but the operational speed of a device is continuously increased.
In terms of optical active devices, lasers based on III-V material, such as InP, GaAs, etc., and electro-absorption modulated lasers have been developed from chip research to mass production, the encapsulated devices of which have been applied, as mature light sources, to optoelectronic fields such as optical communication, optical medical treatment, etc., and the speed of the devices ranges from hundreds of megabits per second to tens of gigabits per second.
Meanwhile, commercial production for silicon-based optical waveguide devices in optical passive devices, such as light beam splitters, AWG, etc., has been achieved for a long time due to their easy process, low optical transmission loss and easy to be coupled with an optical fiber. Passive waveguide material includes a plurality of materials such as silica, silica-on-silicon, silicon-on-insulator, etc.
With the development of future optoelectronic technology, it has become an inevitable development direction for integrated optoelectronic chips to integrate III-V lasers with silicon-based waveguide devices onto one chip, through which not only the cost of devices is reduced but also the high performance of each element is used. Among other things, it is the most practical technical route at present that an optoelectronic chip be flip-chip bonded on silicon-based waveguide materials, because not only various silica waveguides grow on silicon material, but also silicon material has the heat conductivity coefficient that is close to that of metal and is an ideal heat-sinking material for lasers. As a result, silicon material is an ideal substrate material to achieve hybrid integration of lasers with silicon-based waveguides.
There exists a plurality of difficulties in the hybrid integration due to different properties of materials, included in which the optical coupled alignment problem between waveguides of a laser or a detector and silica waveguides, the loading or transmission problem of high frequency signals in a laser or a detector, the complex process, the high cost, and the heat dissipation for the integrated devices, etc. Therefore, a hybrid integrated chip design, which is easy in process, effective, and practical, is urgently desired to solve the above problems.